Velocity Element Glitches

[FlorianW.]

Hey Guys,

i'm using the velocity Element in combination with RSMB in AE and have some glitches in the results.




What am i doing wrong???

Thanks in Advance!

[TomG]

Settings look correct, in as much as I know (as RSMB is a paid plugin, and we don't have a copy to test with directly). Have you also checked in with RSMB support?

Some thoughts - what kind of animation is it, just regular camera and object transforms (no geometry deformation / soft body / other more unusual stuff)? Is Camera and Object motion blur enabled for the scene? The files were saved out as 32 bit? In the problem files, what does the data look like in the velocity pass (a right click in the VFB will let you check the pixel data, so you can see if it is indeed suddenly changing to something unexpected at those points where the resulting blur is different - if it is, then could be something to do with how Corona is writing the data; if it isn't, could be to do with how RSMB is processing it). Can you share an EXR of a problem frame? Does the problem happen on the same frames each time you process it with RSMB, or on different frames (again, could be a clue on whether it's something in the data, or something with how it's being handled)? What kind of camera is it being rendered from? What version of Max, and of Corona?

Thanks!

[FlorianW.]

Hello Tom, thanks for the detailed answer, i'll try to answer them 1 on 1:

1. It's a regular animation, moving camera, moving objects but no deformation!
2. I think i read in an article, if i use the velocity render element both camera and corona global motion blur should be switched of???
3. Yes, Files were saved as 32 Bit exr's.
4. Velocity element attached!
5. Yes, it always happens at the same frame, as far as i saw.
6. Camera is a coronacam.
7. Max 2018.4 & Corona 2.0

https://media.giphy.com/media/1ymoWTVraCB1Z8VCJn/giphy.gif

Thanks

[TomG]

TY for the extra info! Everything still sounds ok there, at least as far as I could tell. Since it's the same frame each time, can you send over the 32 bit with the velocity pass in it? Along with the result from RSMB once blur is applied. I'd be interested to see what the 32 bit values are in the EXR saved from Corona, at the point where the RSMB-calculated blur "goes wrong". You can use the private uploader if you can't share here (https://corona-renderer.com/upload)

[FlorianW.]

done!

[TomG]

Cheers! Will take a look when I can, hopefully not too long.

[TomG]

A quick look in the CIE doesn't show any discontinuities in the data there, it all seems to change smoothly as expected. May want to check RSMB's help pages too, and engage their support or community in taking a look at the EXR. Also, check out their help pages at https://revisionfx.com/faq/motion_vector/ (perhaps there's something up with alpha for instance, as RSMB uses that to decide whether there is "no object" there to blur; or the setting of the Max Displacement value in RSMB). As far as I can tell, everything from Corona is as expected... but whether it's "as RSMB needs" is a different question :)